Field-magnet for electric machines



(No Model.) 3 Sh'eet sSheet 1.

A. SGHMID.

FIELD MAGNET EOE ELECTRIC MACHINES.

No. 519,097. Patented May 1,1894.

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(No Model.) 3 Sheets-Sheet 2. A. SCHMID. FIELD MAGNET FOR ELECTRIC MACHINES. No. 519,097.

Patented May 1,1894.

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(No Model.) 3 Sheets-Sheet 3.

AJSOHMID.

FIELD MAGNET FOR ELECTRIC MACHINES.

No. 519,097. Patented May 1,1894.

- UNITED STATES PATENT FFICE.

ALBERT SCI-IMID, OF ALLEGHENY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, OF

PITTSBURG, PENNSYLVANIA.

FIELD-MAGNET FOR ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 519,097, dated May 1, 1894.

Application filed December 7,1889. Serial No. 332,961- (No model.)

To aZZ whom it may concern.-

Be it known that I, ALBERT SOHMID, a citizen of the Republic of Switzerland, residing in Allegheny,in the countyof Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Field-Magnets for Electrical Machines, (Case No. 363,) of which the following is a specification.

The invent-ion relates to the construction of [O the field-magnets of generators and motors.

The object of the invention is to simplify the construction and lessen the cost of the field-magnets of electric machines and at the same time secure certain improved results.

The invention consists in constructing the pole-pieces of the field-magnets of laminae of sheet iron stamped or cut into the proper form, and supporting the same in a frame of cast metal. The laminae after having been stamped are assembled in the proper relative position and held in any suitable manner, and the molten metal to form the frame is cast about them in suitable molds. The laminae of soft iron may be insulated from each other 2 5 to a greater or less extent by oxide of iron formed upon their adjacent surfaces, thus pre venting the circulation of Foucault currents.

The invention will be described more in detail in connection with the accompanying drawings, in which Figure 1 is an end view of the field-magnet and Fig. 2 a cross-section of the same. Figs. 3, 4 and 5 illustrate details.

Referring to the figures A represents the 3 5 frame of the field-magnet and B, B, field-magnet poles. These poles are composed of laminae or plates 1) of soft iron, such as sheet iron. These laminae are stamped out in the proper shape and size and are assembled in their proper relative positions in the molds. They may be bolted or otherwise secured together as illustrated at c. For the purpose of securing a good union between the sheet iron and the cast iron, some of the laminze may be made of greater length than the others as illustrated in Figs. 4 and 5 so that the ends will afiord openings into which the molten metal will run; someof the laminae may be made with laterally projecting lugs as shown at f, around which the cast iron will flow, thus making the mechanical structure more firm. The field-magnet frame may with advantage be cast in separate portions as shown at a, a This permits the armature to be more easily placed in the field-magnet and se- 5 5 cures a better mechanical construction than would be obtained by forming it in one continuous piece. This form of field-magnet possesses the advantages of laminated field-magnet cores, such as are especially desirable for alternating current apparatus and at the same time secures the cheapness and simplicity of construction of the ordinary cast-iron fieldmagnets.

I claim as my invention 6 1. In an electric generator or motor-for alternating currents, field-poles composed of laminae of sheet iron, a frame for said poles of cast-iron cast about the laminated pole pieces, certain of the laminae projecting into the cast iron frame a greater distance than the others.

2. In an electric generator or motor for alternating currents, field-poles composed of laminae of sheet iron placed in contact with each other, aframe for said poles of cast iron, 7 5 certain of thelaminae having lateral lugs, substantially as described.

In testimony whereof I have hereunto subscribed my name this 5th day of December,

ALBERT SOHMID. Witnesses:

J. M. TATE, J r., J. W. SMITH. 

